Doctest: The Easiest Testing Tool(Chapter 2 of Python Testing Beginner's Guide)
test.txt
1 This is a simple doctest that checks some of Python's arithmetic operations.
2 >>> 2 + 2
3 4
4 >>> 3 * 3
5 10
6
7 Now we're going to take some more of doctest's syntax for a spin.
8 >>> import sys
9 >>> def test_write():
10 ... sys.stdout.write("Hello\n")
11 ... return True
12 >>> test_write()
13 Hello
14 True
15
16 Here we use doctest's exception syntax to check that Python is correctly enforcing its grammer.
17 >>> def faulty():
18 ... yield 5
19 ... return 7
20 Traceback (most recent call last):
21 SyntaxError: 'return' with argument inside generator (<doctest test.txt[5]>, line 3)
22
23 Next up, we're exploring the ellipsis.
24 >>> sys.modules # doctest: +ELLIPSIS
25 {...'sys': <module 'sys' (built-in)>...}
26 >>> 'This is an expression that evaluates to a string'
27 ... # doctest: +ELLIPSIS
28 'This is ... a string'
29 >>> 'This is also a string' # doctest: +ELLIPSIS
30 'This is ... a string'
31 >>> import datetime
32 >>> datetime.datetime.now().isoformat() # doctest: +ELLIPSIS
33 '...-...-...T...:...:...'
34
35 Next, a demonstration of whitespace normalization.
36 >>> [1, 2, 3, 4, 5, 6, 7, 8, 9]
37 ... # doctest: +NORMALIZE_WHITESPACE
38 [1, 2, 3,
39 4, 5, 6,
40 7, 8, 9]
41 >>> sys.stdout.write("This text\n contains weird spacing.")
42 ... # doctest: +NORMALIZE_WHITESPACE
43 This text contains weird spacing.
44
45 Now we're telling doctest to skip a test
46 >>> 'This test would fail.' # doctest: +SKIP
47 If it were allowed to run.
48
2 >>> 2 + 2
3 4
4 >>> 3 * 3
5 10
6
7 Now we're going to take some more of doctest's syntax for a spin.
8 >>> import sys
9 >>> def test_write():
10 ... sys.stdout.write("Hello\n")
11 ... return True
12 >>> test_write()
13 Hello
14 True
15
16 Here we use doctest's exception syntax to check that Python is correctly enforcing its grammer.
17 >>> def faulty():
18 ... yield 5
19 ... return 7
20 Traceback (most recent call last):
21 SyntaxError: 'return' with argument inside generator (<doctest test.txt[5]>, line 3)
22
23 Next up, we're exploring the ellipsis.
24 >>> sys.modules # doctest: +ELLIPSIS
25 {...'sys': <module 'sys' (built-in)>...}
26 >>> 'This is an expression that evaluates to a string'
27 ... # doctest: +ELLIPSIS
28 'This is ... a string'
29 >>> 'This is also a string' # doctest: +ELLIPSIS
30 'This is ... a string'
31 >>> import datetime
32 >>> datetime.datetime.now().isoformat() # doctest: +ELLIPSIS
33 '...-...-...T...:...:...'
34
35 Next, a demonstration of whitespace normalization.
36 >>> [1, 2, 3, 4, 5, 6, 7, 8, 9]
37 ... # doctest: +NORMALIZE_WHITESPACE
38 [1, 2, 3,
39 4, 5, 6,
40 7, 8, 9]
41 >>> sys.stdout.write("This text\n contains weird spacing.")
42 ... # doctest: +NORMALIZE_WHITESPACE
43 This text contains weird spacing.
44
45 Now we're telling doctest to skip a test
46 >>> 'This test would fail.' # doctest: +SKIP
47 If it were allowed to run.
48
testable 1 def testable(x):
2 r"""
3 The testable functin returns the square root of its parameter, or 3, whichever is larger.
4 >>> testable(7)
5 3.0
6 >>> testable(16)
7 4.0
8 >>> testable(9)
9 3.0
10 >>> testable(10) == 10 ** 0.5
11 True
12 """
13 if x < 9:
14 return 3.0
15 return x ** 0.5
2 r"""
3 The testable functin returns the square root of its parameter, or 3, whichever is larger.
4 >>> testable(7)
5 3.0
6 >>> testable(16)
7 4.0
8 >>> testable(9)
9 3.0
10 >>> testable(10) == 10 ** 0.5
11 True
12 """
13 if x < 9:
14 return 3.0
15 return x ** 0.5
